Hello everyone. I was just wondering how to get some of the square law long channel model parameters from the gf180 SPICE file? If one wants to use the gf180 for the design and simulation of an amplifier, can the square law equations be used for the hand calculations of the design? If yes, how can the values of the relevant model parameters like the ones shown in the attached image be extracted or estimated for the gf180? Or is there a better hand calculations method other than extracting model parameters from the SPICE file? @Tim Edwards @Mitch Bailey @Luis Henrique Rodovalho

Sorry, no idea. @Stefan Schippers?

@Emmanuel Innocent( cc@Mitch Bailey) You can get the key nominal parameters from the models, take the BSIM 4.5 document as a reference (for example this one, but there are probably better ones). You can get the oxide thickness Tₒₓ from the TOXM model parameter and the mobility (μ₀) from the U0 model parameter (see in your pdk installation the file:

.../share/pdk/sky130A/libs.tech/combined/continuous/models_fet.spice

). So with patience and some research you can get all the long/wide channel parameters to do reasonably accurate hand calculations. I am not a model / TCAD expert, so anyone with experience in the matter could give better hints. Example: the pfet_01v8 mos transistor (in file

models_fet.spice

):

.subckt  sky130_fd_pr__pfet_01v8  d g s b  mult=1
...
...
.model pshort_model.1 pmos
+ level = 54 lmin = 8E-6 lmax = 2.02E-5 wmin = 7E-6 wmax = 1.01E-3
...
... all model parameters listed
...

you see in above file section the

model.1

bin is valid for long / wide channels so this is a good bin to get model parameters from (no significant deviations for short/narrow channel)

Thank you very much @Stefan Schippers this will be helpful.